Well I have been investigating the current state of database and spreadsheet solutions for the iPhone/iPad, for something I have been working on. It's certainly not as dismal as it used to be, but there's still lots of room for improvement.
I'm not going to list all the apps I've taken a look at or considered or not considered because of some missing feature. I just have some general comments to make about the subject.
One thing you see in Apple's apps, that you don't see in everybody else's, is the understanding that usually you are not standing still while looking at the screen. In fact this was one of the big aha moments for me moving from Windows Mobile to the iPhone.
The classic analogy is the yardsale sign, with 30-100 words in magic marker on a piece of cardboard less than two feet square, tacked so it can be seen from the 55 mph highway. It looks great in your house when you draw it up, with the date and times, a phone number, some key items, and the word YARDSALE nice and large. But what you realize when you get in your car and drive by it at 55 mph, is that the sign is much much too small to read even the word YARDSALE. In fact it probably should be twice as large just for those two words on different lines.
This creates a big challenge for doing real data-crunching on a two-three inch screen. Your font is going to be 4 or 5 or 6 in order to get 2 or 3 pieces of data on the screen. Try to read that while walking. Impossible. Apple, idealistic to the end, thus only puts a tiny bit of data in front of you, which works really well. The challenge is to adapt workflow such that you can work efficiently that way. Thus all the database solutions on the iPhone completely eschew tables. Their only interface is the form, where you can look at the fields from one row at a time. The spreadsheet solution give you the tables. But it's like Windows Mobile all over again. You can zoom in and see one cell, or you can zoom out to see the table but the font is illegible.
That being said I will mention a couple of my favorite spreadsheet solutions (as I need table-view). Google docs works just fine on the iPhone, and even offers editing, though the editing interface is a little clunky. But still this is an amazing and free web solution. Documents to Go is not free, and costs quite a bit for the premium version, but if you get that version you can edit Word, Excel, and Powerpoint directly from DropBox. That means you can swap documents back and forth between people and computers and phones. That's pretty sweet.